What Is VPLS?
VPLS is a class of VPN or Virtual Private Network that connects multiple sites to form a single bridged domain. It is implemented using a MPLS or Multi-Protocol Label Switching Network. That makes it protocol-transparent so that all services, regardless of which location the are physically located at, appear to be on the larger LAN that serves all locations.
What are Typical Classes of Service?
Class of Services or CoS is established in MPLS networks to ensure the performance of each packet on the network. CoS classes include real time for voice and video, mission critical for time sensitive applications such as transaction processing, business critical for applications such as database access, and data for lower priority traffic that isn't time sensitive.
Don't Frame Relay Networks Do The Same Thing as MPLS Networks?
They used to in a simpler way. Frame relay networks use small ATM cells rather than the modern IP network cores of MPLS networks, so they tend to be less efficient. Most carriers are shutting down their Frame Relay networks since the rise of MPLS. The newer MPLS networks tend to be designed for higher speeds to match today's business bandwidth needs.
How Does Label Switching Work?
Label switching technology tags the input packets with their source, destination and quality of service requirements. Tag switches or label routers then efficiently get that packet to its destination intact.
MPLS Network Speeds
MPLS networks can run at any network speed and are being adopted by major carriers as the multipoint to multipoint technology of choice. For this reason, MPLS is fast replacing Frame Relay.